The IRS reminds taxpayers they may have money waiting for them. About 1 million taxpayers who did not file a 2014 federal income tax return have unclaimed tax refunds totaling about $1.1 billion. Here are some things taxpayers should know about these unclaimed refunds:

To collect the money, taxpayers must file their 2014 tax return with the IRS no later than this year’s tax deadline, Tuesday, April 17.

The IRS estimates that half of the refunds are more than $847.

When a taxpayer who is getting a refund does not file a return, the law gives them three years to claim that tax refund. If the taxpayer does not file a tax return within three years, the money goes back to the U.S. Treasury. For 2014 tax returns, the three-year window closes April 17, 2018.

The law requires taxpayers to properly address and mail the tax return to the IRS. It must be postmarked by the April deadline.

The IRS may hold the 2014 refunds of taxpayers who have not filed tax returns for 2015 and 2016.

The unclaimed money will be applied to any amounts still owed to the IRS or a state tax agency. The money may also be used to offset unpaid child support or past due federal debts, such as student loans.

By failing to file a tax return, people stand to lose more than just their tax refund. Many low- and moderate-income workers may be eligible for the earned income tax credit. For 2014, the credit was worth as much as $6,143.

Taxpayers who are missing forms W-2, 1098, 1099 or 5498 for the years 2014, 2015 or 2016 should request copies from their employer, bank or other payer. Taxpayers who are unable to get missing forms can order a free wage and income transcript at IRS.gov using the Get Transcript Online tool. Taxpayers can use the information on the transcript to file their tax return.